The invention relates to a plug-in part for a plug connector arrangement, the plug-in part being in the form of a piece of tubing and having a sealing portion, comprising a sealing element enclosing the piece of tubing in a circumferential direction, and a locking portion with at least one undercut, and it being possible for the plug-in part to be plugged into the receptacle of a coupling part of the plug connector arrangement in order to produce a fluid-tight connection, and for at least one locking element of the coupling part to engage behind the plug-in part in the region of the undercut.
Such plug-in parts are used in plug connector arrangements by means of which pipes or hoses can be connected to one another in a releasable manner. For this purpose, the plug connector arrangement has a coupling part with a receptacle into which the plug-in part can be plugged. By means of locking elements, the plug-in part can be locked in the coupling part. The plug-in part is in the form of a piece of tubing and, adjacent to its free end, has a sealing portion with a sealing element which fully encloses the piece of tubing in the circumferential direction. If the plug-in part is plugged into the receptacle of the coupling part, then the sealing element engages in a fluid-tight manner against the wall of the receptacle, and a locking element of the coupling part engages behind at least one undercut, which is positioned in the region of a locking portion of the plug-in part. The plug-in part is thus secured in the direction of its longitudinal axis in the receptacle of the coupling part, with a fluid-tight connection being maintained in the process.
Such plug-in parts are known, for example, from German Utility Model DE 86 24 767 U1. In order to lock the plug-in part in the receptacle of the coupling part, this utility model proposes the use of a locking plug having two legs and a cross-piece connecting the two legs to one another, the legs each forming a locking element. The plug-in part is in the form of a piece of tubing and has a conical portion which is adjoined by an annular groove which, on its side which is directed away from the conical portion, is bounded by a cylindrical portion. Both the cylindrical portion and the conical portion fully enclose the known piece of tubing in the circumferential direction. The rear side of the conical portion, this rear side being directed away from the front side of the known plug-in part, forms an undercut, and this has two locking elements engaging behind it when the plug-in part is inserted into the receptacle of the coupling part.
The fluid-tight connection between the plug-in part and the coupling part is ensured by a sealing element. If the sealing element is adversely affected, this results in it being possible for a fluid which is routed through the plug-in part and the coupling part to escape out of the receptacle of the coupling part via the locking portion.
It is an object of the present invention to develop a plug-in part of the type mentioned in the introduction so as to reduce the risk of the sealing element being adversely affected.